How to know if a RecyclerView has enough content to scroll?

Question

Currently I am using a RecyclerView with a LinearLayout Manager and an EditText as HeaderView for filtering the content of the list.

I would like to hide the EditText if

Answer 1

RecyclerView can't scroll anymore when the item at last position is completely visible.

In condition that would sound as:

mRecyclerView.getLayoutManager().findLastCompletelyVisibleItemPosition() == mRecyclerViewAdapter.getItemCount() - 1;